| A Heartful of Games | Spain | — | 1 | — |
| A.I Co., Ltd. | Japan | July 1990 | 1 | — |
| Aabs Inc. | Japan | March 8, 2010 | 1 | 1 |
| Aackosoft | Netherlands | 1983 | 27 | 3 |
| Abbey Games | Netherlands | March 19, 2012 | 3 | 2 |
| Abogado Powers | Japan | — | 1 | 1 |
| Abrakam | Belgium | — | 1 | — |
| Absolute Entertainment | United States | 1986 | — | 5 |
| Abstraction Games | Netherlands | 2007 | 3 | — |
| ABX Games Studio | France | — | 3 | — |
| Abylight | Spain | — | 1 | — |
| Accelerate Games | United States | — | — | 17 |
| Access | Japan | 1979 | 1 | — |
| Access Games | Japan | May 30, 1996 | 5 | — |
| Acclaim Games | United States | January 6, 2006 | 1 | 2 |
| Acclaim Japan, Ltd. | Japan | — | — | 1 |
| Acclaim Studios Austin | United States | August 14, 1991 | 20 | — |
| Acclaim Studios London | United Kingdom | 1984 | 14 | — |
| Acclaim Studios Teesside | United Kingdom | 1988 | 2 | — |
| Accolade | United States | 1984 | 9 | 22 |
| ACE Software | Spain | — | — | 1 |
| ACE Team | Chile | 2002 | 4 | — |
| Acheron Design | Australia | 2004 | 1 | — |
| Acid Nerve | United Kingdom | — | 1 | — |
| Ackk Studios | United States | 2013 | 1 | 1 |
| Acquire | Japan | December 6, 1994 | 17 | 4 |
| Acram Digital | Poland | 2014 | 3 | 3 |
| Action Forms | Ukraine | 1995 | 3 | — |
| Active Soft | Japan | — | 4 | 4 |
| Activision Blizzard | United States | July 10, 2008 | — | 3 |
| Activision Value Publishing | United States | August 2000 | — | 5 |
| Actoon Studio | Brazil | — | 2 | 2 |
| Addictive Games | United Kingdom | 1982 | 2 | 2 |
| Adeline Software International | France | 1992 | 2 | — |
| Adelta | Japan | 2014 | 1 | — |
| ADK | Japan | July 1980 | 4 | — |
| Adobe | United States | February 28, 1982 | — | — |
| Adria Games | Poland | — | 1 | — |
| Adult Swim | United States | September 1999 | 1 | — |
| Adult Swim Games | United States | 2005 | — | 6 |
| Adventure International | United States | 1978 | — | 1 |
| Adventure Planning Service | Japan | August 27, 1988 | — | 1 |
| Adventure Soft | United Kingdom | 1983 | 3 | 2 |
| Aeria | Japan | October 30, 2002 | 1 | — |
| Aeria Games | United States | 2006 | — | 1 |
| Aerie Gaming Studios | United States | 2018 | 1 | 1 |
| Aerosoft | Germany | 1991 | — | 19 |
| Aesir Interactive | Germany | — | 3 | — |
| Aeternum Game Studios | Spain | 2019 | 2 | 2 |
| Aether Studios | United States | 2014 | 1 | — |
| Aethon Collective | United States | January 21, 2021 | 1 | 1 |
| Afil Games | Brazil | — | 1 | 6 |
| AFTERBURN | Poland | November 20, 2016 | 1 | 1 |
| Agate Studio | Indonesia | 2009 | 2 | — |
| Agatsuma Entertainment | Japan | — | — | — |
| AGE | Japan | June 12, 1995 | 2 | 2 |
| Ageia | United States | 2002 | — | — |
| Agenda | Japan | November 2, 1990 | 1 | — |
| Agens | Norway | September 6, 2005 | 1 | — |
| AGEod | France | 2005 | 6 | — |
| Agetec | United States | 1998 | — | 13 |
| Ahead Multimedia | Sweden | August 10, 1993 | 1 | 1 |
| Aicom | Japan | 1988 | 3 | 1 |
| Aidem Media | Poland | September 10, 1997 | 4 | 4 |
| Aiming | Japan | May 12, 2011 | 1 | — |
| Airship Syndicate | United States | 2014 | 2 | — |
| Akabeisoft2 | Japan | 2005 | 2 | 1 |
| Akatsuki Games | Japan | December 16, 2021 | 2 | 2 |
| Akatsuki Inc. | Japan | 2010 | — | 1 |
| Akella | Russia | 1993 | 9 | 32 |
| Aksys Games | United States | July 14, 2006 | — | 30 |
| Alawar Entertainment | Russia | 1999 | 19 | 136 |
| Alawar Premium | Russia | — | 1 | 4 |
| Albino Moose Games | United States | — | 1 | 1 |
| Alchemist | Japan | August 14, 1991 | — | 6 |
| ALcot | Japan | 2003 | 2 | 3 |
| Alda Games | Czech Republic | 2013 | — | 1 |
| Alfa System | Japan | 1988 | 14 | — |
| Aliasworlds Entertainment | Belarus | 2001 | 10 | — |
| AliceSoft | Japan | 1989 | 31 | 31 |
| Alien Pixel Studios | Romania | — | 1 | — |
| Alientrap | — | 2002 | 1 | — |
| Alike Studio | Spain | 2014 | 2 | 1 |
| Alim | Japan | March 22, 2013 | 3 | — |
| All in! Games | Poland | 2018 | 2 | 9 |
| Alligata Software Ltd. | United Kingdom | 1982 | — | 1 |
| Allods Team | Russia | 2006 | 3 | — |
| Allumer | Japan | February 1978 | 1 | 1 |
| Almost Human | Finland | 2011 | 2 | 2 |
| Alpha Dog Games | Canada | — | 2 | — |
| AlphaDream | Japan | January 12, 2000 | 5 | — |
| Altar Games | — | 1997 | 3 | — |
| Alternative Software | United Kingdom | 1985 | 2 | 5 |
| Altron | Japan | September 10, 1983 | 9 | 6 |
| Alvion | Japan | 1996 | 1 | — |
| Amada Printing | Japan | July 16, 1956 | 1 | 1 |
| Amanita Design | Czech Republic | 2003 | 2 | 5 |
| Amanotes | Singapore | 2014 | 2 | 2 |
| Amata K.K. | Japan | June 25, 2008 | 1 | 2 |
| Amaze Entertainment | United States | 1997 | 3 | — |
| Amazon | United States | July 5, 1994 | 1 | — |
| Ambiera | Austria | — | 3 | 3 |
| Ambrella | Japan | 1996 | 7 | — |
| Ambrosia Software | United States | August 18, 1993 | — | — |
| Amedio Co., Ltd. | Japan | October 30, 1998 | 1 | — |
| American Laser Games | United States | 1989 | — | 1 |
| Amsoft | United Kingdom | 1984 | — | 3 |
| Amusement Vision | Japan | 2000 | 6 | — |
| Amuze | Sweden | 1996 | 1 | — |
| Amzy | Japan | April 21, 2008 | 1 | 1 |
| Anarchy Enterprises | United States | 1994 | 2 | 2 |
| Anate Studio | Ukraine | — | 1 | — |
| Anchor Inc. | Japan | 1996 | 1 | 5 |
| Ancient | Japan | 1990 | 5 | 2 |
| Ancient Forge | Poland | — | 1 | — |
| Andamiro | South Korea | 1992 | — | 2 |
| Andrade Games | Germany | — | 2 | 1 |
| Angry Demon Studio | Sweden | — | 1 | — |
| Anic | South Korea | May 2013 | — | 1 |
| Anima Project | Spain | — | 1 | — |
| Animation Arts | Germany | — | 4 | — |
| Animation Magic | United States | 1992 | 3 | — |
| Anino Games | — | November 2001 | 2 | — |
| Aniplex | Japan | September 1995 | — | 5 |
| Aniware AB | Sweden | 1992 | 1 | — |
| Ankama | France | June 2001 | 3 | 3 |
| Ankama Games | France | October 2, 2006 | 2 | 4 |
| Another Indie | Taiwan | — | — | 1 |
| Anshar Studios | Poland | 2012 | 3 | 2 |
| Ant Software | United States | 1989 | 3 | — |
| Ant Workshop | United Kingdom | — | — | 1 |
| Antimatter Games | United Kingdom | 2013 | 1 | — |
| Anuman | France | 2000 | 3 | 3 |
| Ape, Inc. | Japan | March 1989 | 1 | — |
| Apeiron | — | 2002 | 1 | — |
| Apex Computer Productions | United Kingdom | — | 2 | — |
| APh Technological Consulting | United States | 1974 | 4 | — |
| Apogee Entertainment | — | 2008 | — | 3 |
| Apogee Software | United States | — | 8 | 9 |
| Appaloosa Interactive | United States | 1993 | 3 | — |
| Appeal | Belgium | 1995 | 1 | — |
| Appelmoes | Netherlands | — | 1 | — |
| Apple Inc. | United States | April 1976 | — | — |
| Applibot | Japan | July 7, 2010 | 2 | — |
| Application Systems Heidelberg | Germany | 1985 | — | 4 |
| AppSir | Philippines | — | 4 | 4 |
| APriori Digital | United Kingdom | June 28, 2013 | 2 | 2 |
| Apus Software | Belarus | 2005 | 4 | 4 |
| AQ Interactive | Japan | October 2005 | 1 | 4 |
| Aqua Pacific | United Kingdom | 1999 | 2 | — |
| Aquaplus | Japan | October 1994 | 5 | 7 |
| Aquiris Game Studio | Brazil | 2007 | 3 | 2 |
| Aquria | Japan | January 8, 2002 | 3 | — |
| Arario Corporation | Japan | June 2007 | — | 1 |
| Arc Developments | United Kingdom | 1984 | 1 | — |
| Arc Games | United States | 2008 | — | 3 |
| Arc System Works | Japan | May 12, 1988 | 51 | 45 |
| Arcadia Project | Japan | August 2002 | 1 | — |
| Arcen Games | United States | 2009 | 2 | 1 |
| ArenaNet | United States | 2000 | 4 | — |
| Argonaut Games | United Kingdom | 1982 | 7 | — |
| Aria | Japan | March 2006 | — | 1 |
| Ariel Co., Limited | Taiwan | November 28, 2017 | — | 2 |
| Arika | Japan | November 1995 | 18 | — |
| Ariolasoft | Germany | 1982 | 2 | 1 |
| Ariolasoft UK | United Kingdom | — | — | 2 |
| Arise | Belarus | 2002 | 1 | — |
| Arkadium | United States | 2001 | 1 | — |
| Arkane Studios | France | 1999 | 8 | — |
| Armor Games | United States | October 2005 | 1 | 3 |
| Armor Games Studios | United States | — | — | 15 |
| Arrowiz | People's Republic of China | 2016 | 2 | — |
| Art & Magic | Belgium | 1991 | 4 | 3 |
| Art Co., Ltd | Japan | 1995 | 3 | — |
| Art Games Studio | Poland | — | 5 | 10 |
| Artdink | Japan | April 21, 1986 | 31 | 13 |
| Arte | Germany | — | — | 1 |
| Arte France | France | June 2, 1986 | 1 | 2 |
| Artech Digital Entertainment | Canada | 1982 | 3 | — |
| Artefacts Studio | France | 1994 | 1 | — |
| ArtePiazza | Japan | November 1989 | 2 | — |
| Artic Software | United Kingdom | — | 1 | 2 |
| ArticNet | Japan | April 4, 2013 | 2 | — |
| Artifex Mundi | Poland | 2006 | 14 | 70 |
| Artificial Life, Inc. | — | 1994 | 1 | — |
| Artisan Studios | Canada | 2016 | 2 | — |
| Artland | Japan | September 14, 1978 | — | — |
| Artoon | Japan | August 27, 1999 | 5 | — |
| Artplant | Norway | 2001 | 2 | — |
| Aruma Studios | Spain | — | 1 | — |
| Arush Entertainment | United States | — | — | 1 |
| Arxel Tribe | — | 1990 | 1 | — |
| Arzest | Japan | June 25, 2010 | 4 | — |
| ASa Project | Japan | March 30, 2007 | 2 | 2 |
| Ascaron | Germany | 1991 | 12 | 4 |
| Ascendant Studios | United States | 2018 | 1 | — |
| ASCII Corporation | Japan | June 24, 1991 | 3 | 12 |
| ASCII Media Works | Japan | April 2008 | 1 | 1 |
| Ashborne Games | Czech Republic | 2020 | 1 | — |
| ASK | Japan | 1972 | — | 1 |
| ASK Kodansha Co., Ltd. | Japan | November 26, 1981 | 2 | 2 |
| Asmik Ace Entertainment | Japan | 1985 | 6 | 12 |
| Asobo Studio | France | October 17, 2002 | 6 | — |
| Aspect | Japan | March 25, 1991 | 14 | — |
| Asphere Innovations | Thailand | 2001 | — | 1 |
| Aspyr | United States | 1996 | 11 | 21 |
| Assemble Entertainment | Germany | 2016 | — | 11 |
| Asteristic Game Studio | Brazil | — | 1 | 1 |
| Astragon | Germany | 2000 | 2 | 16 |
| Astrotale Games | Bosnia and Herzegovina | 2019 | 1 | — |
| Asylum Entertainment | United States | 2001 | 2 | — |
| Asylum Square | Germany | — | 3 | 3 |
| Atari | United States | June 27, 1972 | 11 | 84 |
| Atari Corporation | United States | July 2, 1984 | — | 3 |
| Atari Games | United States | July 1984 | 13 | 9 |
| Atari Interactive | United States | 1998 | — | 1 |
| Atari Program Exchange | United States | February 1981 | — | 1 |
| Atari SA | France | June 1983 | 1 | 11 |
| Atari, Inc. | United States | February 1993 | — | 24 |
| Atari, Inc. | United States | February 1993 | 1 | 17 |
| Atari, Inc. | United States | June 27, 1972 | 22 | 23 |
| Atarisoft | United States | 1983 | — | 1 |
| Atelier 801 | France | October 14, 2011 | 1 | 1 |
| Athena | Japan | July 1987 | 5 | 3 |
| Atlantis Interactive Entertainment | France | 2003 | 2 | 1 |
| Atlus | United States | April 7, 1986 | 1 | — |
| Atomic Games | United States | 1989 | 5 | — |
| Atomic Planet Entertainment | United Kingdom | 2000 | 2 | — |
| Atomic Raccoon Studio | France | — | 1 | 1 |
| AtomicTorch Studio | Singapore | — | 1 | 1 |
| Attention to Detail | United Kingdom | 1988 | 3 | — |
| Attic Entertainment Software | Germany | September 1990 | 3 | — |
| Atypique Studio | France | June 27, 2017 | 1 | 1 |
| Audiogenic | United Kingdom | 1985 | 3 | — |
| August | Japan | 2001 | 3 | 3 |
| Auroch Digital | United Kingdom | — | 7 | 1 |
| Aurogon Shanghai | People's Republic of China | September 28, 2007 | 4 | 1 |
| Aurora Punks | Sweden | — | — | 2 |
| Autobótika | Colombia | — | 1 | — |
| Automata UK | United Kingdom | 1977 | — | 2 |
| Autumn Games | United States | 2007 | — | 2 |
| AV Games | Russia | — | 1 | — |
| Avalanche Software | United States | 1995 | 8 | — |
| Avalanche Studios Group | Sweden | 2003 | 5 | — |
| Avalon Hill | United States | 1958 | 4 | 9 |
| Avalon Interactive | United Kingdom | 2003 | — | 1 |
| Aventurine SA | Greece | 2003 | 1 | — |
| Aviary Films | United Kingdom | June 13, 2007 | 1 | 1 |
| Awaceb | France | — | 1 | — |
| Awaken Realms | Poland | — | 1 | 3 |
| AWE Games | — | 1997 | 3 | — |
| Awesome Games Studio | Poland | — | 1 | 1 |
| Axel Springer SE | Germany | 1946 | — | 1 |
| Axis Games | United States | 2003 | 1 | 1 |
| Axol Studio, LLC | United States | 2015 | 6 | 6 |
| Axyos Games | Georgia | — | 2 | 4 |
| AZAMATIKA | Russia | — | 4 | 4 |
| Azeroth, Inc. | United States | — | 1 | — |
| Âge | Japan | 1998 | 7 | 4 |